Technical
Tips for Harley Davidson custom motorcycle building
and maintenance.

The following is a collection of technical advice articles
regarding the legendary Harley Davidson motorcycle in its many forms. The information
was won through long hours of experience making mistakes and getting lucky.
We make fewer mistakes with experience, but experience comes mainly by making
mistakes.

DISCLAIMER:

FARGONASPHERE.COM takes no responsibility for the accuracy
or appropriateness of any information you might find here. If you attempt
to use this FREE information you do so at your own risk. However, every
effort has been made to provide useful information, and we hope you benefit
from it.

ALWAYS REMEMBER TO REMOVE THE GROUND CONNECTION FROM
YOUR BIKE'S BATTERY BEFORE DOING ANY WORK ON ANY PART OF YOUR BIKE!!!!

IF YOU ARE USING A BATTERY TRICKLE CHARGER AND HAVE ATTACHED
THE GROUND WIRE TO YOUR BIKE'S FRAME, BE SURE TO DISCONNECT THE CHARGER AS
WELL AS THE BATTERY GROUND WIRE!!!!

The HD Shovelhead motor went out of production in 1984.
The motor has always had a bad rep, probably because it was the motor that
AMF bought when it bought the company in 1974. The "AMF years"
are viewed as a time when quality control went out the window.

But is the bad reputation of the shovelhead deserved?
Aren't there some positive reasons one might run a shovelhead motor? First
the obvious differences between the Shovelhead and the Evo:

Tolerances: Overall the Evo is machined to one thousandth inch where the
Shovelhead is machined to five thousandths.

Cylinders: The Evo design uses an iron core encased in aluminum casting
where the Shovelhead is cast iron throughout.

Headbolts: The Evo uses long bolts that extend from the case to the top
of the head, where the Shovelhead uses two sets of shorter bolts - one
set to secure the cylinder to the case, and the other to secure the head
to the cylinder.

There are many other differences, but those presented
here are perhaps the most significant. Shovelheads can be constructed to
be more powerful and more reliable than any Evo. Many racers prefer the
shovelhead because it is easier to modify and capable of tremendous extremes
of operation. You can get an incredible variety of specialized parts, including
high performance cases, pistons, valves, heads and cams for shovelheads.
The engine ain't dead by any means, and is considered by many to be the
best motor Harley Davidson ever made.

In racing applications shovelhead cylinders distort less than
Evo cylinders because the shovelhead jugs are made of cast iron. When under
extreme stress, Evo cylinders (made of aluminum) tend to change their shape
due to unequal stress distribution around the head bolts. This results in
"blow by" between piston rings and the cylinder wall, and a reduction in
power that gets transferred to the pistons. This is a major reason for the
desirability of shovelhead motors in racing.

Although the Evo has higher tolerances, the Shovelhead
can be worked on in a home garage without the need for high tolerancing
machine tools. In this respect, the Shovelhead is the last HD motor to
be designed for the farm-hand. You can wrench the whole thing yourself!
(With a little experience.)

The Evolution engine has earned a reputation for being
more "reliable." In reality, the Evo is indeed a little more reliable,
but a poorly maintained Evo will be much less reliable than a well maintained
shovelhead. The difference is that when the Evo gets out of whack you probably
won't be able to fix it yourself.

You don't need to remove the Shovelhead motor from the
frame to remove the heads or jugs. This means you can inspect and replace
valves, guides and heads as necessary. You can even hone your own cylinders!
The Evo may be more "reliable" but it is also closer to the philosophy
of "no user-serviceable parts inside." The twin-cam 88 is even
less user-servicable. You need lots of special tools to work on any HD motor
after the introduction of the Evo.

So, you may need to change oil more often, and re-torque
bolts, and deal with wear in your valve guides, but you can do these things
yourself instead of paying an expensive company mechanic. If you are of
the philosophy that a big part of riding a bike is being constantly, intimately
aware of how it is functioning, you may find a good set of tools and a
well set up Shovelhead motor is just the ticket. Bottom line is what you
do when you are stuck by the side of the road and can't take anything apart
with limited tools. Evo riders wait for the tow truck. Shovel riders can
unbolt stuff and make repairs.

Did you ever need to torque a shovelhead motor's head bolts? If so,
you know what a pain that can be if you don't have the right tools. After much
struggle, the simple tool shown here was invented. I takes about a half an hour
to make one yourself, and you probably have the tools to do it with right in
your shop. Click on the image to view the Torque Wrench From Hell.

The Oil Pressure and Neutral lights on your dash panel
may be a potential source of disaster. In aftermarket and most factory
models these indicator lights are nothing but 12 volt bulbs mounted in
twist-lock receptacles. Unfortunately, the design of the receptacles leads
to a high potential for short circuits. A small piece of conductive debris
(like a metal shaving) can lodge itself between the inner shell and the
dash, causing the light to turn on in error. If the light is intended to
indicate that the bike is in neutral you may end up trying to start it
in gear. Or, as has happened to me, your oil-pressure light may come on
when there is no loss of pressure!

Fortunately, there is a very simple remedy for the poor
design of these lightbulb sockets. You can use 12 volt HIGH INTENSITY LED's
to replace the bulbs and sockets.

A stock socket consists of a shell with a keyway for the
tiny posts on the bulb, and a center conductor at the base that makes contact
with the center conductor on the bulb. The shell is supposed to be insulated
from the dash by a fiber washer. In theory, the shell should never make
direct contact with ground. In practice, the shell can easily be bent or
contaminated with debris and ground itself. The wiring of the bulbs is
with +12 volts to the center conductor on the bulb, and the ground side
made or broken to provide the indicated signal. Any light that can handle
12 volts and has its ungrounded side connected to +12 permanently, and
its grounded side connected to an oil pressure or neutral switch will do
what the stock assembly does!

So, go to Radio Shack or your local electronic parts supply
house and buy two 12 volt automotive quality HIGH INTENSITY LEDs. If you
can find a mounting kit for the LEDs make sure it fits into the holes where
the lightbulb sockets were installed in your dash. If you can't find a
mounting kit, it is possible to use grommets.

WIRING: As with all solid state devices, you must be careful
to limit the current that can go through the LED. Look in the specs for
the LEDs you are using and find the maximum current allowed by the devices.
You can then use OHM's Law to derive the necessary resistance to put in
series with the LED. In case you don't remember, Ohm's Law is expressed
as E=I*R, or "Voltage is equal to Current times Resistance."
You can find the resistance by simple algebraic substitution: R=E/I, or
"Resistance is equal to Voltage divided by Current." Voltage
is in Volts, current is in Amperes and resistance is in Ohms.

Example: For a current of 60 milliamps (ma) and a voltage
of 12 volts the required resistance will be E(12)/I(.06) or 200 Ohms.

If the LED you choose is designed to be used in instrumentation
it may not need to have an external current-limiting resistor. Read the
instructions that come with the LED carefully.

Unless your LED panel light assembly has a built-in resistor,
you need to place a suitable resistor IN SERIES with the LED, between
the +12 volt source and the LED. IMPORTANT:
If you don't use a resistor of the proper value the LED will quickly burn
out. If you DO wire it correctly, the LED will last longer than the bike,
(or longer than YOU for that matter), and it won't be affected by vibration.

You know those old-fashioned bayonette bulbs that come with aftermarket
license plate and running light kits? Well, those bulbs have filaments mounted on
long stalks. It turns out that those bulbs are vulnerable to vibration. The stalks
that support the filaments vibrate like tuning forks, and quickly break the attached
tungsten.

I used to go out for a putt and come back to find the running light
filament broken, but the stop light filament was always fine. The running light
filament was mounted on the longer stalks, so it was evident that the length of the
mounting stalks was causing the failure. What I did was to re-wire the stop and
running lights using plug-in bulbs, securing the bulb sockets to the brake light
housing using velcro strips. Those bulbs haven't failed yet, even though they
get the same rough treatment as the older style bulbs. Now I'm saving my money
for LED arrays.

Whatever brand of carburetor you run, there are things
you need to know if you expect to get efficient performance from your carb.
A carburetor is a simple device. It takes air (a gas) and gasoline
(a liquid) and mixes the two together in an "aerosol" or fog.
The air/fuel mixture can exist in different proportions. If there is more
fuel compared to constant air, the mixture is said to be "rich."
If there is less fuel compared to air, the mixture is said to be "lean."

A lean mixture will run your engine HOT, in fact, so hot
that your valves and pistons will literally burn up! Whatever you do, especially
with a shovelhead motor, avoid a lean condition. Follow your carburetor's
instructions to the letter, and carefully dial in your engine by starting
with a rich mixture and working toward a mixture that is slightly rich,
but never lean. A tell-tale sign of lean running is when the motor backfires
through the pipes and sputters through the carb. The motor is trying to tell
you something, and it pays to listen. A well set-up carb will give good
solid acceleration without backfires or sputtering.

Things that can go wrong:

Your carb has gaskets and O-ring seals. Be very careful
to install all the seals when re-assembling the carburetor! For example,
if you fail to install the O-ring seal that sits on top of the accelerator
pump nozzle in an S&S Super E carburetor the float bowl will be at
atmospheric pressure and leak fuel constantly around the nozzle. As air
is drawn through the Venturi on its way to being mixed with fuel, the air
will cause a vacuum over the opening left by the absent O-ring and pull
fuel right up out of the float bowl. This appears as a constantly rich
condition, with little control offered by changing jets.

As you drop the float bowl make sure you pull straight
down, and avoid tearing the float bowl gasket. If you tear the gasket,
the float may not be able to rise high enough in the bowl to close the
gas needle valve. If this happens, flooding of the engine will result.
You might get "washdown", where raw gasoline washes down over
the pistons and into your oil system. Once this happens you should change
the oil immediately because gas is a solvent and will destroy your oil's
lubricating qualities.

An air/fuel mixture sensor is a great tool to help you
diagnose carburetor problems. The device is based on a sensor that is installed
in your bike's tailpipe. You have a welder install a threaded "boss"
in the pipe and you thread the sensor into it so that the sensing element
is exposed to exhaust gases. The sensor hooks up to an electric meter that
measures from 0 to 1 volt. Such meters are readily available on the market.
A good source is "Split Second" who can be found on the Web and
sell racing engine tuning devices. Here's a link to Split
Second

An air/fuel meter will detect the fuel mixture you are
running and enable you to select the right jets to optimize your mixture.
It is by far the best way to give yourself some peace of mind on this important
issue. It will also detect when your carburetor is leaking, or when you
have not installed that one tiny O-ring that makes all the difference in
the world. Most important: It will warn you when your fuel system goes
south and your motor starts to run lean - BEFORE IT BURNS UP!

Unless you run a Constant Velocity (CV) carb you will
need to change jets at some time, especially when your travels lead you
to radically different altitudes (+-7,000 feet). As you climb into the
Sierras you will notice that black smoke begins to emerge from your tailpipe.
Your motor will blubber and perhaps your plugs will foul. There you are
by the side of the road as the cages roll by and the drivers grin at you
and your predicament. What to do? You need to change jets.

As altitude increases, air pressure decreases. This means
that the bike that runs OK at a lower altitude will run richer as it climbs.
A CV carb will automatically compensate by maintaining the same pressure
inside the carb as outside, but a variable velocity device will meter out
fuel at the same rate, but mix less air with it. This creates the rich
condition that causes all your problems.

To change jets you need to remove the plug from the float
bowl, drain the gas (making sure you turned OFF the petcock first!) and
then unscrew the main jet and replace it with a lower numbered jet. The
numbers on a S&S Super E carb refer to the diameter of the metering
hole in the jet. Now, the ideal thing would be to change BOTH the intermediate
AND the main jets, but to change the intermediate jet you would have to
remove the float bowl entirely. At the side of the road this means possibly
losing the O-Ring at the top of the accelerator pump tube (see above).
Besides, the whole messy operation can be avoided if you install a variable
jetting device like Dial-A-Jet.

The Dial-A-Jet was invented by a racer who got a competitive
edge by being able to quickly adjust his carb to accommodate atmospheric
conditions at a given race track. For years, these devices have been hidden
in carburetors and jealously guarded as trade secrets of racing bike riders.
With the Dial-A-Jet you just pull over to the side of the road when your
Split Second air/fuel mixture meter indicates you are running rich (or
that black smoke starts coming out of your tailpipe), loosen one screw
a turn, and dial a leaner condition! And, even better, on your way back
down the mountain you can quickly enrichen the mixture in the same way.
One danger of changing altitudes is that your attempt to lean out the mixture
as you go up can lead to an overly lean condition when going down, and
you can wreck an engine by running it for a half an hour in a TOO LEAN
condition!

Air/Fuel mixture is extremely important to the health
of your motor. If you run a motor too lean under load for even a short
period of time you risk detonation and meltdown! What this means is that
your engine will overheat due to excessive oxygen in the burn and fire
at random during the four-stroke cycle. What this means is that your parts
will melt or burn, destroying bearing surfaces and resulting in the necessity
of costly repairs.

The air/fuel mixture is the ratio of oxygen to gasoline
that gets to your cylinders from the carburetor. A "rich" mixture
will have a low air/fuel mixture whereas a "lean" mixture will
have a high ratio of air to fuel. You can buy oxygen sensors these days
that are placed in the exhaust pipes and send a signal (a voltage that
varies from 0 to 1 volt usually) and allow monitoring meters to show the
proportion of air to fuel in a running engine's mix. Air/fuel monitoring
makes it easy to know for sure that the adjustments you make to your plugs
and jets will produce a safe and efficient fuel mixture.

One very good product is made by Split
Secondof Santa Ana, California. If you want
to see an installation of the Split Second product on my bike, check it
out here:

Jetting is more of an art than a science. The use of an
air/fuel mixture sensor makes the process more scientific, but it also
reveals the complexity of the jetting process.

You start the jetting process conservatively, making sure
that you will be running rich rather than lean. You can get to a good starting
configuration by reading your carburetor's instruction manual and selecting
jets that are wider in diameter for your engine type and displacement.

Assuming you have selected a rich combination, you will
notice that the air/fuel meter shows rich no matter what you do. Gradually,
after a series of trial runs, you will notice that the meter indicates
rich while accelerating and bobbles around from rich to lean depending
on your throttle position. As you decelerate to a stop the meter will show
lean, and will quickly show rich as you accelerate. The thing to observe
is that the mixture is NOT CONSTANT. There is no magic value that will
show a constantly rich or constantly lean condition. Instead you will observe
a range of values that hover around an ideal point.

Now the artist in you observes this behavior and you get
an idea of what might be good for your riding conditions. There are many
factors that come into play. Your accelerator pump is one of them. Depending
on how you have your jets set up, and how much the accelerator pump is
putting out, and how rich your dial-a-jet is set, you will find that hard
acceleration forces the air/fuel ratio into the full rich zone, where cruising
with a little gas feed runs ever so slightly to the rich side. UNDER NO
CIRCUMSTANCES should you run on the lean side while the throttle is open.
Full closed on the throttle, coasting to a stop, will run lean, but that
is the only time you should see a lean condition!

Also remember that the actual air/fuel mixture shown by
the air/fuel meter may be richer or leaner depending on the temperature
of the sensor. This is why it is a good idea to use a heated sensor (four
wire) rather than an unheated (two wire) sensor. It is always a good idea
to keep things a little rich at the expense of gas mileage in favor of
reduced expensive repairs to an overheated or detonated engine.

After jetting the S&S Super E Shorty carb and getting it just
right, wouldn't ya know, the gas mileage was about 20 to 30 miles per gallon.
Bummer. Seems the Super E runs rich, but gives lots of power at the high
end, which sounds about right for the drag strip but doesn't cut it when
what you like to do is cruise around and take long trips.

So, after some research, and on the good advice of
the guys at Frisco Choppers, a Mikuni HSR42 carburetor was purchased.
It took about nine hours to install. It could have taken less time, but
I didn't want to make any mistakes - like have it fall off or leak gas on
my leg. After a long Friday evening and into Saturday morning, and a
good night's sleep, and some last minute adjustments, the bike started
right up but popped through the carb when the throttle was blipped.
No sweat. Used a screwdriver to adjust the air screw - in fat, out lean -
and in a few seconds the motor started to sound mellow.

Although the Mikuni is impressive and runs well, it
is a little less elegant than the S&S Super E. The Super E is simple in
design, with few moving parts. It fits well under the tank and the
filter housing doesn't protrude as far. Eventually I found that the
mileage wasn't really improved by running the Mikuni and I went back
to the S&S because it is easier to adjust and maintain.

Have you ever wondered why an open-faced helmet is better
than a full-face when you ride a hog? Safety arguments aside, the open-face
helmet gives you the ability to hear your engine! Why is this a good idea?
You might miss those telltale noises that can signal serious trouble about
to happen.

One day I changed helmets and took a ride. As I was puttin'
along I heard crisp pops coming from the engine. The closed helmet had muffled
these sharp sounds. After the ride I thought hard about the noise, which was
occasionally accompanied by a backfire. I decided I was hearing the sounds
of detonation - where your engine is running lean enough to ignite the fuel
mixture when no spark is present. I found out that detonation can also be
caused by running spark plugs that are too "hot."

So I went right down to my local auto-supply and bought
a couple of Splitfire plugs. After installing these beauties the popping
went away and so did the backfiring! Not only that - the bike starts better
and runs better. The old plugs were platinum, and apparently were of the
"hot" variety, where the Splitfires were just the right heat range for the
shovelhead. So far, they haven't fouled, and the detonation problem (which
could have seriously damaged my pistons or the cylinder walls) has gone
away for good. I bought a couple of spares...

Each gasoline engine is built with specific characteristics. The bore
and stroke is designed to provide optimum power and torque. The
compression ratio is the ratio of cylinder volume when the piston is at Top Dead
Center (TDC) to volume at Bottom Dead Center (BDC). A high compression
ratio (like 9.5:1) will produce more power than a low compression ratio
will. This is because the fuel/air mixture is compressed into a smaller
volume before it is ignited by the spark. This increased compression
results in a hotter and more powerful propagation of energy from the burning
fuel.

High compression engines require plugs that have smaller spark gaps. A
smaller gap will create a more predictable spark. A spark that takes too
long to cross the gap will be more likely not to make it, or to make the gap at
the wrong time. This means you get timing problems that can easily lead to
detonation. For a high compression engine you may want to experiment with
smaller gaps (on the order of .028 to .025) until you get no misfires at any
RPM. The gapping is very subjective and needs a lot of trial and error
before you get it right. Of course you don't want to gap down to much less
than .025 or short out the plug as this could ruin your coil. Just keep in
mind - high compression means short spark.

Another reason to gap down is to create a more certain spark for kick
starting. A wide gap that might be used with an electronic ignition and
platinum plugs may be too wide for the small amount of energy produced by your
kick on the starter arm. A smaller gap will allow a smaller amount of kick
to produce a spark and increase the reliability of your kick start shovelhead.

Indexing means that you use washers of calibrated thickness to raise the plug
in the plug hole. You may want to index if you are running high
compression pistons if only to make sure the pistons don't come into contact
with the grounding electrodes. Indexing also enables you to orient the
spark in the best position to ignite your mixture. You can purchase plug
indexing kits that will enable you to point the spark at the center of the
combustion chamber, favoring the exhaust port. This is said to be the best
position to put the spark, but there is much dispute as to whether indexing does
any appreciable amount of good. In any case, indexing gives you the
ability to point the spark so it is visible to the fuel mix. This can
improve the reliability of a kick starter. For kickers, the spark gap,
orientation and fuel mixture are critical.

If you are getting poor gas mileage (around 25 miles per
gallon instead of high 30's) it is natural to suspect the carburetor.
The carb may not be the problem. No matter what the displacement of
the engine, a carb should get you anywhere from the low thirties to
the mid forty miles per gallon. The Mikuni carb, for example, will run
fine right out of the box for any displacement from 74 through 96 inches or more.
The only exception might be running at high altitude, over 10,000 feet,
where it may need to have a larger needle. Even then, you don't need to
change anything unless that's where you live. For short trips the carb
is very tolerant to altitude and will run rich but not extremely so.
If you are not getting good gas mileage and you have tried everything
from jetting to adjusting the choke or enrichener you should take a
look at the fuel line.

Is your fuel line running from the petcock to the carb
by way of the space between the cylinders? Does it touch the heads,
cylinders or case anywhere? Does your chewing gum lose its flavor on
the bedpost overnight? Yes? You might have a problem.

Particularly in the case of the shovelhead, with those
iron jugs, a lot of heat builds up between the cylinders. If your gas
line runs between them and comes in under the carb, that extreme heat will make
the gas expand and force itself into the carburetion system under pressure.
This will create a very rich condition. If your bike starts to load up
as it heats up you should suspect that the fuel line is getting hot.

The solution is to re-route the fuel line over the top
of the motor instead of between the jugs. You can align the petcock spigot
so it points in just the right direction to allow the fuel line to press up
under the tanks and come down over the top of the carb and connect to the
banjo spigot on the Mikuni. The Mikuni spigot swivels to allow you to
do this. You should try to use the shortest fuel line that maintains the
greatest distance from the engine. In addition, you should use
slitted corrugated plastic heat-resistant tubing that slips over the
fuel line to provide an additional amount of insulation
and heat protection. I added a couple of strap ties - one at the carb
to keep the line away from the rocker box, and one that pulls the fuel
line up toward the frame. This arrangement keeps the fuel line in
place so it doesn't fall down on the front rocker box.

There are two basically different ignition switch designs
used on Harley Davidson motorcycles. The first consists of a brass bar
that is attached to the ignition switch center post. The bar is rotated
by the centerpost, and its ends snap into place between copper raised buttons
that surround the centerpost and connect to the bike's electrical system.
The rotating bar connects the buttons together to cause a current to flow
between them.

When electronic ignition systems began to be used on HD
bikes, a new kind of ignition switch was introduced. Dubbed the "electronic"
ignition switch, this device consists of a rotating copper plate that is
attached at its center to the switch centerpost. The plate is shaped so
that indentations at various positions on the plate come into contact with
copper strips embedded in an insulating material. The plate maintains contact
with combinations of these strips. It is really a misnomer to call the
switch "electronic" because the switch itself contains no electronic
parts - only the plates that slide over each other.

The difference between the two switches is significant
only if you have an electronic ignition system. One thing you DON'T want
to happen at any time while the ignition system is operating is to interrupt
power to it. The older version of the ignition switch, with its rotating
bar, would interrupt current briefly as the switch was rotated to turn
on the lights. When this happened, current to the ignition module was interrupted.
This interruption of current flow would reset the electronic module. So,
the new switch was invented to make sure that the current flowing to the
ignition system was uninterrupted when the switch was rotated to turn the
lights on!

MORAL OF STORY: If you install an electronic ignition
system on a bike that previously was running points you should replace
the ignition switch with an "electronic" ignition switch.

Motorcycles VIBRATE. The plastic insulation on wires used to
connect your bike's electrical components together can be removed by vibration.
If a wire is wedged between a circuit breaker or other object and the head of
a bolt, for example, that wire's insulation can be worn down to the point where
it will expose the wire to contact with the bolt head. This can happen faster
than you think. To avoid this kind of problem, be sure to wrap all wiring in
coiled plastic insulation. You can buy this kind of insulation at your local
automotive supply store. The thick insulation will provide a barrier between
the wire and any exposed metal with which it might come into contact.

So, you bought a Hitachi starter and solenoid assembly
and you wish to install it on your new custom Harley Davidson softail.
You may have also purchased a starter mounting assembly. This article does
not cover the mounting of the starter - only the electrical installation
of it.

It's really easy, but there are some things that you should
know in order to keep it that way.

ALWAYS REMEMBER TO REMOVE THE GROUND CONNECTION FROM
YOUR BIKE'S BATTERY BEFORE DOING ANY WORK ON THE STARTER, OR ON ANY OTHER
PART OF YOUR MOTORCYCLE!!!!

IF YOU ARE USING A BATTERY TRICKLE CHARGER AND HAVE ATTACHED
THE GROUND WIRE TO YOUR BIKE'S FRAME, BE SURE TO DISCONNECT THE CHARGER AS
WELL AS THE BATTERY GROUND WIRE!!!!

Wiring the starter involves the use of one screw connector
and one rather large bolted terminal. The screw connector is marked "S"
on the right hand side of the solenoid when viewed from the rear. The solenoid
is the small housing that sits on top of the starter motor . There is also
a terminal marked "R" on the other side, but that terminal
will NOT deliver electric current to the starter. The "R"
terminal is used in some applications to "Return" some of the
current to the ignition system while the starter is being run. You don't
need to connect anything to the "R" terminal if you just want
to do a basic installation. The "R" designation is confusing
because it is easy to imagine that "R" stands for "Relay."

You wire the +12 volt output of the starter relay to the
"S" post. The solenoid is grounded to the frame, so there is
no ground wire necessary. The large bolted connector on top of the solenoid
housing is used to deliver twelve volts at FULL BATTERY OUTPUT CURRENT
to the starter motor. You need to connect the largest battery cable you
can find to the POSITIVE (+) post on your bike's battery (that's right,
directly to the post) so that the maximum current will be delivered to
the starter.

How It Works

Inside the solenoid housing there is a coil of wire that
surrounds a ferrous (iron) bar. The bar is free to move inside the coil
so that when current is applied to the coil the bar is thrust outward toward
the starter ring gear. The starter gear is attached to the solenoid core
and is pushed toward the ring gear by it. When a certain point is reached
in the travel of the solenoid core, the core forces a copper disk to contact
two terminals simultaneously. One of the terminals is attached directly
to the starter motor, and the other is attached to the high current connection
and the POSITIVE (+) post on your bike's battery.

When the connection is made, the starter gear is already
meshed with the starter ring gear. When the current flows through the disk
attached to the solenoid core the starter motor turns the gears. Basically,
the starter motor and solenoid are just a couple of coils of wire that
use electric current to cause mechanical motion.

What Can Go Wrong?

There are a few things that can make your starter fail
to operate. Keep in mind that, in order to function, a small current (at
+12 volts) must flow through the solenoid coil. Then the solenoid core
must move toward the ring gear, and carry with it the contact disk. Finally,
the contact disk must bridge between the two terminals inside the solenoid
housing in order to allow the high current to flow from the battery through
the starter motor.

1. You may have mistakenly connected the +12 volt wire
from the starter relay to the "R" post on the solenoid. This
will not do any harm, but it won't activate the solenoid either! Be sure
to connect the wire from the starter relay to the "S" post on
the solenoid.

2. The starter relay may not be wired correctly. You can
verify that it is wired correctly if you test the +12 volt output using
a volt meter. Harley Davidson repair manuals contain wiring diagrams that
will help you to correctly wire the starter relay.

3. If you used too much force in tightening the high amp
terminal it is possible that you twisted the contact inside the solenoid
housing out of position. You can check this by removing the end cover on
the solenoid. The cover is located at the rear of the solenoid housing.
Inside you will see the solenoid core with the contact disk and the two
contact posts. You can see if the contacts are not in alignment, and WITH
THE BATTERY GROUND WIRE REMOVED you can test to see if the disk contacts
both posts at once. If not, adjust the posts so that they pass current
through the disk when the solenoid is thrown forward. When you tighten
the high amp post, it is a good idea to hold the bottom nut with a wrench
while tightening the top nut.

If the above suggestions still do not result in a working
starter, there may be more serious problems that may require you to have
the starter serviced by someone with the ability to test and repair or
rebuild electric starters.

The starter pinion gear attaches to a splined endshaft
on the starter gearbox assembly. The pinion gear is the gear that spins
the ring gear attached to the clutch basket. Unless this gear is installed
correctly the assembly can come apart and leave you with a pile of aluminum
filings and a milled out extension shaft end support!

When installing the pinion gear on the splined endshaft
you will install a splined washer, a spring, a flat washer, the pinion
gear, a lockwasher, the extension shaft and the bolt that holds the whole
thing together - in that order. The extension shaft is locked to the pinion
gear by a lockwasher that fits between the gear and the extension shaft
itself. IT IS EXTREMELY IMPORTANT THAT THE BOLT IS TIGHTENED ENOUGH TO
COMPRESS THE LOCKWASHER FULLY! If the bolt is not tight, the bolt will
work loose and eventually cause the pinion gear to become detached from
the endshaft spline.

It may be necessary to RED Locktite the screw that holds the
endshaft to the starter jackshaft spline. You can use a propane torch (CAREFULLY!) to heat the bolt and break the Locktite bond if you wish to
remove the bolt at a later date. Of course, WHENEVER YOU USE AN OPEN FLAME
ANYWHERE NEAR YOUR BIKE YOU SHOULD DRAIN THE GAS TANK(S) into a legal
and safe container.

The problem is that the endshaft turns in a clockwise
direction as the starter is activated. Although the endshaft is held in
a bushing, the resistance to turning will cause the endshaft to apply a
force in the counterclockwise direction, tending to unscrew the bolt that
holds the endshaft in place and compresses the lockwasher. It would be
ideal if the endshaft bolt was left-hand threaded, but then it wouldn't
mate with a stock starter gearbox endshaft spline.

Lubrication is necessary whenever materials are brought
into frictional contact. The need for lubrication is found in everything
from sex to motorcycle engines (not much difference in Spider's opinion)
and providing the proper lubrication for your scoot is the key to remaining
free of mechanical trouble. Yes, they are called "troubleheads",
but you can greatly reduce the trouble by simply taking good care of your
machine.

A shovelhead motor (manufactured by HD from 1966 to 1984)
requires ASA 50 weight oil. The oil should be changed every 1,500
miles after the motor has been broken in. Shovels require more frequent
oil changes than Evolution motors. The manual says you should not use multigrade
engine oil, but there are differing opinions on this. Some shovelhead fanatics
insist that 20/50 weight oil is better than straight 50, reasoning that
HD didn't start using multigrade until the early seventies. Since the shovelhead
came into existence in 1966, single weight 50 was all that was used. Perhaps
HD would have recommended 20/50 weight oil if it were in use when the shovelhead
was invented.

The advantage in using 20/50 is that starting is easier
due to the lower viscosity. It's your decision as to whether you want to
use straight 50 or multigrade 20/50. A good source of motor oil for your
shovel is (of course) Harley Davidson.

During break-in, the shovelhead lube requirements depend
on your break-in philosophy. One school of thought has it that oil needs
to be changed frequently. This philosophy is based on the idea that fresh
oil provides the best cutting characteristics and allows the mating parts
to wear more effectively. Following this philosophy you would do your first
change at 50 miles, with subsequent changes at 250 miles until you reach
a total of 1,500 miles, after which the motor would be broken in. The other
dominant philosophy is that you should do your first oil change at 500
miles and one more at the 1,500 mile mark. The rationale behind this philosophy
seems to be that the oil accumulates a lot of metal particles that aid
in cutting the metal surfaces. Spider tends to favor more frequent oil
changes during break-in.

It's a pure necessity to change your oil every 1,500 miles
when you own a shovelhead motor. But be sure to flush the oil bag every
other oil change! If you don't, you risk clogging your bike's oil pump
or oil lines and siezing the engine.

Here's how to do it: Go to your local lumber yard, gas
station or hardware store and purchase five gallons of kerosene. The stuff
comes in (and must be transported in) special blue five gallon drums. The
drums are re-usable. Diesel fuel will work just as well. Be sure to purchase
a kerosene pump to make life a whole lot easier. When you get this stuff
to yer shop, drain your oil as usual and put a quart or two of kerosene
into the tank. You should be careful not to drain the kerosene into the
oil pump, so it is a good idea to remove the supply hose and plug the tank
with wood dowels. Golf tees might work for this. Every once in a while
you should remove the oil bag entirely.

If you have not removed the oil bag from the bike, with
the kerosene in the tank, sit on the seat and rock the bike back and forth
so the kerosene mixes with sludge on the bottom of the tank. After some
suitable rock and roll, remove the plug and drain the kerosene safely away
into a container for environmentally safe disposal or re-use. You might
want to do this a couple of more times. There will be black sludge in the
kerosene until it runs clear. Make sure all the kerosene has drained out
before you fill the tank with oil. Kerosene is a solvent and will destroy
the lubricating properties of yer liquid gold.

It is much easier to do a thorough job if you remove the
oil bag from the bike beforehand. In this case, slosh that kerosene around
in the tank for fair thee well before you dump the stuff. You should see
some black sludge come out. Wash the tank with kerosene until the stuff
that comes out is clean kerosene. Again, make sure there is no kerosene
left in the tank before you re-assemble the bike and fill the tank with
oil.

The stuff used to be called "Vitriol" before
its chemical properties were understood. All that was known in the Eighteenth
Century, however, was that the stuff would eat holes in damn near anything,
and it would just keep eating. And this is the stuff we now use in wet-cell
storage batteries that we keep just under the seat on our bike. It's called
"sulfuric acid", and it should be approached with sincere respect.

Just a little of this stuff on your hands will get into
your eyes when you rub them. It could leave you blind. If you get a drop
on your clothing it will work silently until, when you wash your clothing,
you will find holes. Even in indetectable quantities, it will oxidize anything
it touches until it is neutralized by combining with the substance it is
in contact with.

Of course you don't want to get this stuff in your eyes!
If you do manage to get it in your eyes, call 911 immediately and get to
an emergency room. If you have a first aid kit, be sure it has an eye cup
and basic solution to wash any acid out of your eyes as soon as possible.
The stuff just won't give up. Likewise, you don't want it on your skin
or in your mouth.

If you are using a wet storage battery (with little plastic
caps along the top) be sure to attach a plastic tube of the proper size
and battery-acid resistant construction to the spill port on the battery.
Lead the plastic tubing down to a point below the frame and secure it there
so it doesn't bind and get blocked. This way any acid that spills will
end up on the road and not on your expensive frame or chrome. One drop
on chrome will eat through and rust in no time.

You should spill some sodium bicarbonate (like Arm and
Hammer) to cover any area in which you store or charge storage batteries.
Place the batteries on this sodium bicarb matt and it will neutralize any
acid that spills out and protect your tools and work surfaces.

If you have a 3" belt open primary and you find tranny
oil on the pavement where you stop yer bike it could mean that you are
loading the tranny's bearings. Your belt may be too tight.

When properly adjusted, the primary belt should have
nearly 3/4" free play when cold. As the motor warms up and you use
the clutch the aluminum pulleys will expand and the belt will tighten.
When fully hot the belt should still have some free play, but not as
much as when cold.

If the pulleys are not properly aligned, the belt will
tend to crawl off or rub against the sleeve on one side or the other.
Fortunately, when the clutch basket pulley is properly square with the
drive pulley the wide belt will easily keep its position when loose
or tight.

The important thing to remember is that if the belt
is as tight as a drum it will overload the bearings and you will
eventually have a fluid leak that won't stop, and certain damage to
the bearings.

Find that you just can't get good gas mileage no matter
how you adjust your carb? Does your stroker need to be revved up to 4000 rpm
just to go 75 mph? You may need to take a look at your Final Drive Ratio!

The Final Drive Ratio (FDR) is the PRODUCT of the ratios of
your primary drive sprockets (or pulleys) and the ratio of your secondary (or final)
drive sprockets (or pulleys). In a formula, this can be expressed as
(T/E)*(W/C), where T is Transmission sprocket circumference, E is Engine sprocket
circumference, W is rear Wheel circumference and C is Countershaft circumference.
Each circumference is measured in sprocket or pulley teeth.

Given a typical setup, the stock configuration is usually
very near 1.5 for the primary, and around 2.2 for the secondary. The
FDR for a stock bike might be around 3.3. But wait a minute, you're
running a stroker motor. You should know that you don't want to run
anywhere near redline, which happens to be at 4,500 rpm. You want to stay
below 4,000 rpm to avoid unusual wear and tear (like leaving aluminum on the
walls of your cylinders). A stroker wants to run with about a 2 ratio
for the secondary. This means a FDR of about 3. This way you will keep
the revs down and make use of all that torque. For a typical setup you
will be revving at about 2500 rpm when going 60 mph. Now, these numbers
are highly general, and depend on lots of factors, not least of which
is the diameter of your rear wheel.

Be CAREFUL not to get the FDR much below 3.0, as this will
put too much stress on the drive train components.

A 10% decrease in the FDR may translate into
about a 10% increase in your gas mileage, but not necessarily. Turns out
that the energy required to move your bike is the same regardless of
what your drive ratio may be. What this means is that the fuel that is
burned will be about the same to go a given distance, no matter how
much mechanical advantage you obtain. However, there will may be SOME
change in your gas consumption. It really depends on the changes you make
to your riding style based on the new sprocket ratio.

Back in the good ol' days, when men were men, and gun slingers
roamed the West, nobody knew or cared what an oil slinger was. Besides, oil
wasn't needed so much as buffalo grease. But if you ride a Hawg you better
know what an oil slinger is and use one - or you might find yerself stranded
by the side of the road with a frozen clutch pushrod or disintegrated
thrust bearing!

Especially when you are running an open belt primary, you need
to keep oil flowing over all the internal surfaces of your tranny. An oil slinger
does that quite well. What it is is a metal disc with castellations around the
edge (notches) that pick up oil from low down, under the mainshaft and
clutch pushrod in the right-side housing. It slings that oil all over the
innards of the cover, so it gets onto the thrust bearing and the pushrod.
Although the manual says you should fill the tranny to just under the
filler opening, if you run an open primary you know that the fluid will
end up leaching out of the end of the mainshaft. You can't keep the tranny fluid
level high enough to keep that pushrod covered, so the oil slinger can save
you trouble and money.

J&P Cycles sells a kit that includes the thrust bearing,
oil slinger, pushrod and fork. The oil slinger slides onto
the pushrod just behind the thrust bearing washer and locks into a couple
of flats on the rod. For just under thirty bucks you can buy some peace
of mind.

One day you arrive home after a brisk ride on yer chopper.
You notice that black gook is all over yer rear wheel rim and on your chain guard!
A puddle of oil is forming under your clutch basket. "What the fuck?" you say.

Oil puking out of your tranny is a sure sign that your mainshaft
oil seal isn't doing its job and needs to be replaced. You need to remove the
clutch basket and countershaft drive sprocket to expose the seal. Pry it out with
a screwdriver, and replace it with a new seal.

The oil seal is made of a flexible plastic like neoprene. It has
a tension spring surrounding the pressure-fit hole, and a cavity surrounding the spring.
Install the seal with the spring and cavity facing the transmission body. When
installed, you will see the flat side of the seal facing you.

The seal needs to be seated firmly
by setting it carefully using a hammer and dull screwdriver or flat-ended punch.
The oil seal must be seated flush with the bearing behind it, so it is pressure-fit
against the bearing. It should be seated to refusal, evenly, but not pounded back so hard
as to break the plastic or dislodge the bearing. A sharp tool can break through
the plastic, so be careful!

When you want to run aluminum rims, such as those made
by Akront, you need to be aware of problems that can occur due to the use
of dissimilar metals.

Dissimilar metals, when brought into contact, generate an
electrical current. The current comes from electrons that are present in
dissimilar quantities in the atoms of the two dissimilar metals. Especially
in the presence of a catalyst (like sea water), electrons will migrate from
the material with an excess of them to the material that has a relative
electron deficit. In the process, an oxide is formed in the sacrificial material.
For example, aluminum will rob electrons from iron and create aluminum oxide
and iron rust. The chrome on your spokes will flake off.

When you run aluminum rims you MUST install stainless steel
spokes! If you don't, you will find those spokes turn to rust very quickly,
with potentially disastrous consequences. The stainless steel spokes cost
about thirty bucks more than their chromed iron counterparts, but this cost
is minor compared to the cost of a failure of a spoke, a punctured inner tube,
and a potentially fatal crash.

The cam you are running will have a profound effect on
the performance of your motor. This seems obvious, but the lack of understanding
of how cams work, and what they do, can rob you of the full enjoyment of your ride.

A camshaft consists of hardened steel "lobes" that are
arranged to raise and lower your pushrods, and open and close the motor's valves.
Depending on the dimensions of these lobes, the valves will be held open a lesser
or greater distance, for a greater or lesser amount of time. The amount the
cam's lobes move the pushrods is called "lift", and the length of time the valves
are held open is called "duration."

Stock HD cams are designed to provide a modest amount of lift
for a factory-specified duration, and the stock design is conservative. It is
meant to provide good performance without putting too much stress on the valve train.
Without too much danger, however, you can improve the performance of your engine
by installing a higher lift or longer duration cam. BE CAREFUL, however, not
to install a new cam while your bike is under warranty. It may void the warranty!

There are as many cam designs as there are bikes, it seems. You can
get great cams from Andrews, S&S, Crane, and a host of other manufacturers. There are
so many options it is hard to make a choice. But you can get a rough idea of what you
want if you know how cams work, and how they influence your motor's characteristics.

If you want to ride around town on a Sunday or take leisurely trips
in the countryside you may not even want to know what cam you are running. If the bike
is stock you will be happy. However, if you want a little better performance you might
want to get a little more aggressive. Using the Andrews cam numbers, you might want
to run a J grind, an A grind, or maybe a B grind cam. The J grind will give you better
power with a smooth idle, and is just a little better than the stock H grind. An A grind
will raise your valves a little higher and keep them open a little longer. It can be
bolted in without modifying your heads. An AB grind uses a longer duration exhaust to
help your motor run a little cooler, and it gives a little more lift, which improves
high RPM (high end) power somewhat.

If you have high-lift springs, and your valves have been properly
clearanced, you can run a more aggressive cam like the Andrews C grind. This cam
is about as tall as you can get, but you pay a price in more frequent repairs. Still,
on the drag strip this cam will put out monster power where you want it - at around
5000 rpm on up.

In general, high lift long duration cams are for high power at high
revs. The lower lift and shorter duration cams will skew the power curve
down so you can get more low end torque at the expense of high-end power. With less
aggressive cams you will also have less maintenance, because the springs and pushrods
don't do as much work. Less aggressive cams will also give you better gas mileage and a
smoother idle. If you use a kicker you will find the bike easier to turn over as well,
and because of the increased air velocity you will find the mixture ignites easier.

Don't think that you need to use an aggressive cam if you are
running a stroker motor. If you run a stock grind, or a less aggressive performance
cam like the A grind, you will still get a power increase simply from the increased
displacement. In addition, you will get improved idling because the higher volume
of air flowing through a smaller valve opening will create a higher velocity in
the carb at low revs. This improves the idle over what it would be if you were
running a high lift cam. So don't worry too much about matching
the cam to the displacement or compression ratio when considering the use of a
lower lift cam with high displacement engines.

IMPORTANT: The DURATION of a cam can be shorter or longer
depending on your cam's unique specifications. It is important to keep in mind
that short duration cams can contribute to a problem known as DETONATION.
Detonation occurs when your fuel mixture explodes rather than burns. The subject
of detonation is so complex that a full page or web site would be required to
explain it fully, so no attempt to do that will be made here. Suffice it to say
that extreme detonation can destroy an engine in ten seconds! A high combustion
ratio (above 9:1) and/or a short duration (when the valves are kept open a
shorter amount of time) can compress the mixture enough to make it explode
rather than burn. Normal combustion is not an explosive process. Instead,
a "flame front" is generated by the spark plug, and this flame front expands
outward, burning fuel and providing energy as it does so. During detonation,
however, the fuel explodes, often at the wrong time in the cycle. This puts
enormous stresses on pistons and plugs, and can literally blow holes in pistons.
Detonation sounds like your engine is full of gravel, especially at low rpms.
Detonation can be cured by running the correct high octane fuel, reducing
the compression ratio, adjusting for richer carburation, using cooler plugs,
increasing the cam duration, adjusting timing, or a combination of these methods.

Using a high lift cam with a stock or lower displacement
engine may be an exercise in futility. It is essential to follow
the manufacturer's instructions carefully, because cams often require head work
in order to keep the valves from coming in contact with each other or with
pistons. In addition, special springs, spacers and keepers may be necessary.
Unless you are a drag racer, you should get all you want from your motor by running
a stock or modest performance "bolt-in" cam.

The "valve train" begins with the cam and ends with the valve
itself. Along the way many problems can occur. Tappets consist
of a tappet body with a small hole in the side that admits oil to the lifters.
A lifter is a device that sits within the tappet body and transfers the motion
of the tappet body to the pushrod. The tappets are equipped with
rollers that rest on the cam lobes and transfer the positions on the lobes upward
to the pushrods, then to the rockers, and finally to the valves.

You can run hydraulic or solid lifters. Hydraulic lifters have
been stock in HD bikes since 1948. Hydraulic lifters receive oil under pressure
(12 to 35 psi) from the engine and use that oil to damp the motion of a small piston
that is connected to a pushrod. The small amount of oil in the hydraulic cylinder
provides a cushion against shock as well as thermal expansion compensation. As the
motor heats up the cylinders and heads expand upward. So does the oil in the
lifters. With hydraulic lifters you get increased reliability as well as less wear
and tear on the valve train - up to a point.

Hydraulic lifters are just the ticket for average street cruising
and touring, but look out when you roll on the throttle and rev that engine! You can
exceed the lifter capacity, forcing the oil out of the hydraulic cartridge and
possibly damaging your engine. The solution, if you want to push the motor to its
limits regularly, is to install solid lifters.

Whether you install solid lifters or convert your hydraulic lifters
to solid, you will be able to run a more aggressive cam, and you will be able to
twist that throttle as much as you like. However, you will need to adjust those
pushrods more often, and you will need to deal with damage due to increased stress
on the valve train.

It's all a matter of what you want to do with that bike. If
you want to spend time on the drag strip and street riding isn't important, you will
want to run a high lift cam, and use solid lifters. In fact, if you run an Andrews
3 grind or an S&S 514 on up (for example) you MUST use solid lifters.
If you use your bike on the street or for touring you will want the reliability
and decreased maintenance requirements of an hydraulic lifter set.

Shovelhead riders may be interested in upgrading to Jims Powerglide
tappet blocks. These blocks are machined to accept Evolution tappets, so you
get the benefits of Evo technology, including higher revs and lower maintenance
in you shovelhead motor. The kit comes with hydraulic tappets and lifters ready
to install. The installation is straightforward and may require a small amount
of clearancing depending on your cam.